List of variables in the datafiles (forest_data_2010_pub.txt and forest_data_2016_pub.txt) associated with Vindstad et al."Can novel pest outbreaks drive ecosystem transitions in northern-boreal birch forest?". 

Block    = ID of 2*2 km landscape block.
Transect = ID of 50-m sampling transect within each landscape block.
Tree     = ID of tree within each sampling transect. Multiple row for a tree means that the tree has more than one stem (one row per stem).
Species  = Tree species. BP=Betula pubescens. Jun = Juniperus communis. SA = Salix spp.
Diam     = Diameter of stem in cm at 1.3 m height. 
Height   = Height category of stem. 1 = 1.3–2 m. 2 = 2-4 m. 3 = >4 m.
Single   = Categorical variable indicating if a tree is single-stemmed or has multiple stems. S = Single-stemmed (monocormic). M = Multi_stemmed (polycormic).
Vital    = Vitality category of stem. L = Living stem with no visible loss of branches. L1 = living stem with <1/3 of branches dead. L2 = living stem with 1/3-2/3 of branches dead. L3 = living stem with >2/3 of branches dead. D = Dead stem without foliage. 
Basal    = Presence of basal sprouts for a tree. 0 = No sprouts. 1 = 1-10 sprouts. 2 = >10 sprouts.   
Sapl     = Number of saplings per transect.  
Meters   = Length of sampling transect in meters.
Period   = Year of sampling. 2010 or 2016.